In its strongest and purest form, meditation is reaching an altered state of consciousness where you become the instrument which can change and alter all the vibratory frequencies of your body. Only saints can reach or have reached this state.
Normal humans can meditate and (try to) get into a deep sense of relaxation. The deep state of relaxation that a human being can enter is not the same as the saint meditation state, but is a first step towards this.
It is a common misconception that meditation is about sitting in silence and closing your eyes. Meditation, by definition, is an altered state of consciousness. When we go silent, more often than not, the chatter in our heads only gets louder. So how do you meditate to reach an altered state of consciousness? Here’s what Her Holiness Guruji Sri Sri Poonamji says about chanting as a meditation: